An organic light-emitting device is a device in which a thin film including a fluorescent or phosphorescent organic compound is sandwiched between electrodes. In the organic light-emitting device, electrons and holes are injected from the respective electrodes to generate exciton of the fluorescent or phosphorescent compound, whereby the organic light-emitting device emits light when the exciton returns to a ground state. Recent progress of the organic light-emitting device is remarkable, and the organic light-emitting device is characterized in that the device can be provided with a high luminance at a low voltage applied, a variety of emission wavelengths and high-speed responsiveness and it can be made thin and light weight. From this fact, it is suggested that the organic light-emitting device have potential to find use in a wide variety of applications.
However, in the present circumstances, an optical output with further higher luminance or higher conversion efficiency is needed. Further, when the application of the device to a full-color display or the like is taken into consideration, the emission of blue, green, or red light with good color purity is needed. However, a problem concerning the emission has not been sufficiently solved yet.
As methods for solving the above-mentioned problems, there are disclosed examples, in Japanese Patent Application Laid-Open No. 2007-15961, Japanese Patent Application Laid-Open No. 2007-169581, Japanese Patent Application Laid-Open No. 2007-191603, U.S. Pat. No. 6,852,429, and U.S. Pat. No. 7,233,019, that a pyrene derivative is used as a constituent material of an organic light-emitting device to thereby improve light emitting efficiency, color purity, and the like of the organic light-emitting device. Further, U.S. Pat. No. 6,849,348 discloses an example that a fluorene derivative is used as a constituent material of an organic light-emitting device to thereby improve light-emitting efficiency and the like of the organic light-emitting device.